Heavy cannabis use could be a cause of Maori having the world's highest lung cancer rate, groundbreaking research suggests. Many Maori from children to kaumatua use cannabis in "epidemic proportions", says a study by Richard Beasley of the Medical Research Institute in Wellington. But cannabis might not be as safe as the proponents of its legalisation say. A paper by Professor Beasley on the health effects of cannabis was among the research that prompted Wellington coroner Garry Evans to urge last week that government policy on illicit drugs be changed from "harm minimisation" to campaigning against drug use. The paper...